Devices for facilitating breathing and producing artificial respiration



July 29, 1958 H. GOODNER 2,845,061 DEVICES FOR FACILITATING BREATHINGAND PRODUCING ARTIFICIAL RESPIRATION Filed May 27, 1955 2 Sheets-Sheet 1INVENTOR.

Monroe Hurry Goodner ATTORNEYS July'29, 1958 M. H. GooDNER 2,845,061

DEVICES FOR FACILIT'ATING BREATHING AND PRODUCING ARTIFICIAL RESPIRATIONFiled May 27, 1955 2 Sheets-Sheet 2 FIG? FIGB nvVENToR. y Monroe HarryGoodner ATTORNEYS United States Patent- DEVICES FOR FACILITATINGBREATHING AND PRODUCING ARTIFICIAL RESPIRTION Application May 2,7, 1955,Serial No. 511,501

19 Claims. (Cl. 128 29) This invention relates to devices foradministering gas, such as oxygen, air or other gases, or a mixture ofgases to facilitate breathing or for other purposes.

Such devices are attached directly or indirectly to a face mask whichtits over the patients mouth and nose or to a tracheal tube.

When the device operates to supply a relatively constant ilow of oxygen,air or other gases to a patient who is capable of natural breathing, itis referred to as an inhalator. Where the device is used for aidinghuman beings or animals in instances where breathing is hindered orrequires artificial aid or stimulation by the application alternativelyof positive and negative pressures, as, for example, in cases ofasphyxiation caused by drowning, poisonous gas, poliomyelitis, heartattack, or the like, it is referred to as a resuscitator.

It has been found that there is great need for a device which issufliciently flexible in operation that it can be shifted substantiallyinstantaneously from applying one set of alternating gas pressures toanother substantially different set of gas pressures, as, for example,from ap.- proximately 14 mm. positive pressure and 11 mm. negativepressure to approximately 27 mm. positive pressure and zero negativepressure. In some cases, as, for example, When a patients air passageshave been inamed and swollen by poisonous gases it is necessary, inorder to maintain breathing, to apply intermittently positive pressuregreat enough to force open the patients airpassages and admit air to thepatients lungs. In such cases exhalation may be accomplished by thepatients lungs without applying negative pressure, it being desirable,however, during the exhalation period to reduce or eliminate positivepressure. In cases Where it is discovered that a patients air passageshave become closed, or partly closed, it may be necessary to shiftimmediately from low alternate positive and negative pressuresordinarily used in artificial respiration, or from supplying acontinuous ow 4of oxygen, air, or other gases as when the device isemployed as inhalator, to supplying a higher positive pressureintermittently with periods in between for exhalation. Such greaterpositive pressure applications would of course be used only in extremecases, but where it is discovered that the patients condition demandssuch treatment it must be possible to supply it substantiallyinstantaneously.

An object of the invention is to provide improved apparatus of the abovedescribed kind.

Another object is to provide a device capableV of shifting eflicientlyand instantaneously from applying one set of gas pressures to anothersubstantially different set o f gas pressures, as for example, fromapproximately 14 mm. positive pressure and 11 mm. negative pressure toap,- proximately 27 mm. positive pressure and zero negative pressure.

Another object of the invention is to provide a cornpact portable devicewhich is highlyI flexible in operation and capable. f beine employed inthe several'r ways and for the several different purposes indicatedabove.

2,845,061 Patented July 29, 1958 'ice Other objects of the inventionwill be apparent from the following description and accompanyingdrawings taken in connection with the appended claims.

In the accompanying drawings in which are shown by way of illustrationseveral possible embodiments of my invention:

Figure 1 is a plan view of a horizontal section taken in line 1 1 ofFigure 2;

Figure 2 is a side elevation of a vertical section taken in the line 2 2of Figure l;

Figure 3 is a fragmentary side elevational view;

Figure 4 is a top plan view of the member 14.

Figure 5 is a bottom plan view of member 14;

Figure 6 is a side elevational view taken on the line 6 6 of Figure 4;

Figure 7 is an end view of the valve closure element shown in Figures 1and 2;

Figure 8 is a face view of a washer comprising part of the valveassembly, and

Figure 9 is a side view of the means shown in Figure l for adjusting thenegative pressure bias.

While features of the present invention have more general application,the invention has its preferred embodiment in a relatively small,compact, portable device, which is preferably arranged for directconnection to a gas administering mask arranged for positioning over apatients face, or nose and mouth, to administer oxygen, air, or othergas for inducing or promoting respiration, aiding breathing or otherpurposes. It is obvious, however, that many variations of constructioncanbe made without departing from the invention, such as changes inshape and construction of the parts, the inclusion of a lleXible hose orother coupling between the device and the mask, and the elimination ofthe means to convert the device into an inhalator, where sucharrangement is not required.

While a preferred embodiment of the invention is described herein, it iscontemplated that considerable variation may be made in the method ofprocedure and the construction of parts without departing from thespirit of the invention. In the following description and in the claims,parts will be identified by specific names for convenience, but they areintended to be as generic in their application to similar parts as theart will permit.

Referring to the drawings, the resuscitator and inhalator shown thereincomprises, in general, a substantially cylindrical sheet metal casingformed of a short section of sheet metal tubing 1l) and the generallyrounded or domeshaped ends 12 and 13. The end 13 has a central openingthrough which is inserted the tubular section 14a of the member 14 whichfits within end 13 but is flatter than end 13 providing an air chamber14h between them after they are assembled. Tubular section 14a is fittedinto a tubular ferrule 15 comprising part of gas administering mask 16.Gas is supplied to' the device through a gas inlet coupling assembly 11to which is coupled a glas supply hose 18 connected to a source ofregulated gas supply. The device can be of a relatively small size, for*example, a resuscitator and inhalator constructed as, shown in thedrawings has been made having a diameter of only 2% inches, and weighingapproximately thirteen Quncesl,

Tubular portion 11)'v of the casing comprises a short pic of thin-walled`tubing, externally threaded at each end. While. the device may be usedin any position encl` wall 12 will be described, for convenience, as thetop of the device. End wall 152 comprises a dome-shaped pressed Sheetmetal Gap` having a Cylindrical imite/,friaHit-tht@adedY flange 19 atits outer edge adapted to screwl onto .the unrestv end oftubuler'section10.. A. round centralnening isproyided in top wall 12, the portion,Zlofthe:

wall bordering on the opening being curved inward to provide a smoothlycontoured recess.

Bottom end wall 13 carries a ange 22 at its outer edge formed similarlyto flange 19 to screw onto the lower end of tubular casing wall 10. Theopening at the center of dome-shaped bottom wall 13 is of a relativelylarge diameter and projecting axially outward through it is the tubularsection 14a of the member 14. Member 14 fits within member 13, leavingthe air space 14b between them, and has inlet and outlet safety valvestherein. Surrounding said central opening in end 13 are a plurality ofapertures 13a to supply air into the space 14b. Tubular section 14a isadapted for insertion into the ferrule 15 attached to the mask 16 whichmay be of conventional form and construction.

A pair of diaphragms comprising an upper diaphragm 27 and a lowerdiaphragm 28 are clamped in horizontal position within the casing,dividing it horizontally into three chambers, namely an upper chamber29, a middle chamber 30 and a lower chamber 31. Diaphragms 27 and 28 maybe formed of any suitable flexible impervious material such asimpregnated cloth, or thin corrugated metal. They are clamped on attheir outer circular edges between the inwardly extending upper andlower anges a and 10b of tubular casting 10, on the ring 27a, and theupwardly extending ilange 14e` of member 14, respectively.

A valve housing 36 is floatingly carried by diaphragm 27 and 28, thevalve housing being suspended between the centers of the diaphragms. Thehousing is centered within the casing and prevented from turning, andthereby twisting the diaphragms, by the arms 23 and 24, pivotallyconnected to said housing by pivots 23a and 24a, respectively, and tothe gas inlet coupling assembly by pivots 23b and 24b, respectively.Housing 36 comprises a metal casting provided with suitable gas passagesand a valve chamber, which a's shown is a cylinder 37 in which aslidable valve closure element 38 is carried. The valve housing 36 alsocarries a venturi 39 and the valve assembly 37, 38 serves to direct gasthrough suitable passages in the housing 36 to the venturi for purposesof supplying positive and negative gas pressures to the patient, as willbe more fully described.

Diaphragm 27 and 28 each have central apertures and are each clamped intheir central areas by a pair of clamping washers or discs. For example,diaphragm 27 is clamped between circular metal washers 40 and 41 whichare held against the two faces of the diaphragm and which have centralopenings registering with the centrol opening in the diaphragm.Diaphragm 28 is similarly clamped between washers 42 and 43. The upperend of iloah'ng valve housing 36 has an external threaded portion 45which extends through the central aperture provided in diaphragm 27 andclamp washers 40 and 41,

and a hollow internally threaded nut 46 is screwed onto 45 therebyclamping the upper end of housing 36 in the central opening in thediaphragm. A screw 46a provided with a screw-driver slot 47 is used toclose the bore in nut 46 through which access may be had to the jet 71to clean it and venturi 39. The lower end of housing 36 carries threadedaxial projection 48 which extends downward through the central apertureprovided in diaphragm 28 and is clampedthereto by clamp nut 49 which istightened against lower clamp washer 42. An internally threaded lowercap 65 is screwed onto projection 48. Cap 65 has an integral circularflange 65a which extends to within a short distance of the inside wallof tubular portion 14a of member 14 and is provided with perforations65b so that the flange protects the inside of the casing from theentrance of foreign particles and still permits free gas passage throughand around the flange. A screw-driver slot 65e on cap 65 permits readyremoval for cleaning jet 72 and Venturi 39.

Housing 36 is connected by a section of flexible rubber or plastictubing 50 (Figure 1) to gas coupling assembly 11 in order to convey gasfrom the supply source to the floating valve housing. In addition, avalve control arm 51 comprising a straight piece of spring metal rod isrigidly supported in the casting of gas coupling assembly 11 and extendsaxially through gas supply tube 50 and the gas passage 52 of gas inletnipple 53 which comprises part of valve housing 36, into cylinder 37where the end of valve control arm 51 is received in central transversepassage 54 in valve closure element 38, so that element 38 is supportedby spring arm 51 (see Fig. 7).

Valve cylinder 37 has its axis parallel to the axis of the device andhence parallel to the direction of motion of oating valve housing 36 asdiaphragms 27 and 28 are exed. Gas inlet passage 52 enters cylinder 37in the mid-portion of its cylindrical side wall. The bottom wall ofcylinder 37 is provided with an annular ridge 55 surrounding gas passagesection 56a which together with sections 56b and 56e makes up a gaspassage leading from the valve to chamber 57 inside cap 46. A plate 58carrying an annular ridge 59 similar to ridge 55 is screwed into theinternally-threaded upper end of valve cylinder 37 and seats against ashoulder at the lower end of the threaded section to provided a secondvalve seat. Plate 58 has a central opening 60 leading into a smallchamber 61 above the plate which is closed by a screw cap 62 threadedinto the top of the cylinder. A gas passage 63 made up of sections 63aand 6311 drilled through the casting forming housing 36 extends down tolower end 48 of the casting communicating with a small chamber 64 insidelower cap 65 which is threaded onto the externallythreaded lower end 48of the casting, as clearly seen in Figure 2.

Valve closure element 38 comprises a sliding metal block of generallyrectangular shape having annular ridges 66 and 67 on its upper and lowerfaces opposing ridges 59 and 55, respectively, at the ends of thecylinder. The diameter of ridges 59 and 66 is made larger than thediameter of ridges 55 and 67 to require greater force to unseat member38 from 59 than from 55 to cause the device to provide greater positivegas pressure for inhalation than negative gas pressure for exhalation.As seen most clearly in Figure 7 the four corners of block 38 arerounded off to provide cylindrical bearing portions which can slide onthe inside cylindrical wall of cylinder 37 while still permitting gas tofreely pass around the element 38 from gas inlet passage 52. Element 38is drilled with a central transverse passage 54 which is of reduceddiameter at its mid-portion to form a loose socket into which the end ofvalve control arm 51 extends as seen in Figure 7.

Interposed between element 38 and stationary valve seat ridges 59 and 55are a pair of flexible washers 69 and 70 having a generally rectangularshape with the corners cut oil. to provide cylindrical bearing surfacesengaging the inside wall of cylinder 37 as shown in Figure 8. It'will beevident that valve closure element 38 is suspended on control arm 51 ina relatively stationary position so that as floating valve housing 36moves up and down in response to motion of diaphragms 27 and 28 element38 will be shifted into contact with one or the other of washers 69 and70, these washers in turn being held against ridges 59 and 55 to cut olithe gas ow through one or the other of passages 63 and 56. Valve controlarm 51 is suticiently resilient, however, to permit it to yield slightlyso that, as long as the gas pressure in cylinder 37 exceeds that in thepassage which is closed by element 38 by an amount sucient to overcomethe restoring force of spring arm 51, the valve will remain closed.However, when the movement of housing 36 has been suicient to build up arestoring force equal to the gas pressure the valve will suddenly besnapped from one end of the cylinder to the other, thereby to open onepassage and close the other.

Casting 36 comprising the valve housing is drilled along one side toprovide a venturi passage 39 having one end tion of the ring to a fewdegrees in either direction.

opening into the middle chamber 30 between diaphragms 27 and 28, and theother end opening into gas administering chamber 31 beneath diaphragm28. Holes are also drilled in casting 36 from both the upper and lowerends in alignment with the venturi passage and a pair of tubes 71 and 72are affixed in these holes to provide jet passages of the requireddiameter extending from chambers 57 and 64, respectively. The materialof casting 36 is cut away in a smoothly rounded manner at the ends ofventuri 39 to deflect gases issuing from the venturi while stillpermitting either of jet tubes 71 and 72 to project a jet of gas intothe venturi on the opposite cycle.

Upper chamber 29 is open to the atmosphere by virtue of the spacebetween central opening 20 and cap 46 and the presence of additionalvent holes 74 in end Wall member 12. Lower chamber 31l is normallyclosed and in communication only with the face mask 16 but is providedwith safety inlet and outlet valves 25 and 26, respectively, which whenunseated communicate through dish-shaped member 14 with the space 14bbetween it and casing end member 13. Member 14 has therein two circularopenings 25a and 26a.- Opening 25a is ordinarily closed by the circularvalve member 25b which seats on the inner surface of member 14 and issupported at one end of spring arm 25C, the other end of which is fixedto the inner face of member 14. When the pressure within the operatingchamber defined by diaphragm 28 and member 14 is reduced beyond apredetermined amount, valve 25 will open to admit air into the operatingchamber to be supplied to the patient. Opening 26a is ordinarily closedby the circular valve member 26b which seats on the outer surface ofmember 14 and is supported on one end of spring arm 26e, the other endof which is fixed to the outer surface of said member 14. Ordinarilyvalve member 26 will remain closed, but it will open when the pressurewithin said chamber becomes greater than a predetermined amount toexhaust gases from said chamber and thereby reduce the pressure thereinand in said face mask. (See Figures 2 and 4.)

Because of the air space between member 14 and end wall 13, both saidintake and exhaust valves are protected from contact with externalobjects and from being inadvertently closed or held down, as, forexample, by the thumb or fingers of a person holding the device. Thevents 13o in member 13 provide a supply of air into space 14b at alltimes for it is impossible for all of these openings to besimultaneously closed inadvertently by the position of the thumb orfingers of the person holding the device.

An adjustable gas vent is provided in wall of middle chamber 30comprising a slot 75 cut part way around wall 10, and a threaded ring 76which is threaded onto the upper threaded portion of cylindrical wall 10below flange 19 of the top wall. slot 77 corresponding to slot 75 in thecasing wall and the outer surface of the ring is knurled to permit thering to be turned manually to bring slot 77 into register with slot 75to a greater or lesser extent. A short pin 78 extends in from ring 76through slot 75 to limit the rota- When ring 76 is turned to oneextreme, slot 75 will be closed by the ring while at the other extreme apassage for the entrance and exit of air or other gases is provided bythe aligned slots 75 and 77.

A one-way valve 79 is also provided in the wall of chamber 30 andcomprises a hollow screw 80 having a gas passage 81 extending throughits stem, and the cross passage 82 to prevent the valve failing if disc84 becomes lodged across the inner end of screw 80. Screw 80' passesinward through wall 10 into a small valve chamber 83 containing arectangular valve disc 84 of mica or other light sheet material whichseats against an annular ridge S5 surrounding an opening leading fromthe valve chamber into chamber 30. When the gas pressure outside chamber30 exceeds the pressure inside, disc 84 will be Ring 76 is provided withaV pressed against ridge 85 to close the valve and prevent However, whenthe to ex the diaphragm 28 and therefore the pressures which will beexerted in the operating chamber 31 and from there communicated to thepatient through the tubular section 14a of member 14 and face mask 16.As

shown herein, the friction member 87 is a curved leaf spring which ispivotal-ly mounted at one end on screw` 24b projecting from the casingwall, specically cou-y pling 11 and at the other end on screw'24a whichprojects from the boss 36a on housing 36. Arm 24 is also mounted on saidscrews and acts as a retainer to hold member 87 against the coupling 11and housing 36. Extending through arm 24 into contact with member 87 isthe adjustingscrew 88 by which the extent of frictional contact ofmember 87 on housing 36 may be controlled.

Also extending from the casing wall is a spring mem- I ber 89 which issubstantially U-shaped and comprises upper and lower arms 89o and 89bwhich press on the housing 36 in opposite directions. As shown, the endsof said spring member are secured to, and .movable with, the ring 90which is rotatable around chamber 83, i. e. around an axis which is atright angles to the axis of the housing 36, to increase the biasingforce exerted on the housing in one direction and to correspondinglydecrease the `biasing force exerted on the housing in the oppositedirection. This second spring 89 is thus a second frictional memberwhich is employed in combination with said first spring member 87 toregulate the positive and negative gas pressures relative to oneanother. By this means adjustment of the positive pressure applied tothe operating chamber and face mask can be readily varied a few degreesfrom a given positive pressure such as, for example, 14 mm. and thenegative pressure can be varied from a given negative pressure, such as,for example,-

For shifting instantaneously between two sets of gas pressures having agreater differential, for example,f27 mm. positive pressure and zeronegative pressure, a third and larger leaf spring 91 is provided,together with toggle switch means 94 for moving said spring from opera-rtive `to inoperative position. Said spring 91 may be either integralwith or secur-ed to a bearing block 93 which is pivotally mounted on atubular spacing member 93a supported by said screw 24bbet'ween its headand said arm 24, for movement toward and away from the housing 36 aroundscrew 24h. It is normally positioned to press on the housing 36 as, forexample, by contact with the arm 24, to bias the housing to greatlyincrease the amount of gas pressure necessary to move the diaphragm 28in the direction which controls the supply of positive pressure to theoperating chamber and the face mask. By suitable adjustment of screw241; the additional bias provided by member 91 for increasing thepositive gas pressure may be made just sufficient to oiset atmosphericpressure in the locality where the device is used and thereby cause thenegative pressure developed during alternate movements of the diaphragm28 and housing to be substantially Zero.

. The toggle switch 94 comprises the thumb piece 94a which is externalto the casing, the intermediate narrow shank portion 94h comprising aball which seats within a socket within the casing wall, and thebifurcated portion 94e extending into the casing. Between the arms ofportion 94C is a pin 95 which serves as a stop against which rides thespring 96 which is secured to the casing 10 at 96a and gives the togglea snap action as pin 95 passes the high point of its curvedpath'wherethumb piece 94 is raised or lowered. Inwardly projectingportion 94C extends under the free end of said spring member 91 and whenin one position leaves the spring 91 free to press upon the housing 36,through arm 24, and when in its other position engages and lifts it outof contact with the housing. Thus, when the toggle switch 94 is in oneposition the device will operate at the set of pressures ordinarilyemployed for resuscitation, such as, for ex ample, 14 mm. positivepressure and 1l mm. negative pressure, and when the toggle switch ismoved to its other position the device will immediately operate on asubstantially different set of pressures, such as for example,approximately 27 mmypositive pressure and zero negative pressure.Pressure in the order of 27 mm. positive and to 3 or 4 mm. negative aredesired in such cases Where the patients air passages have becomesubstantially closed, due to swelling or presence of mucus or foreignmatter, and it is necessary, at least momentarily, to supply gas underpressure much greater than the usual pressure employed in resuscitationin order to open the air passages and get oxygen into the patientslungs.

Since no novelty is claimed herein for the gas coupling assembly, only abrief description of it is given. It comprises a metal casting 97mounted against the inside of cylindrical wall in middle chamber 30 andhaving a threaded nipple 98 extending out through an accommodatingopening in wall 10. The casting is clamped in the opening by a nut 99threaded onto nipple 98 and bearing against a washer 100 shaped toconform to the outer surface of wall 11. A cylindrical passage 101extends through nipple 98 and terminates in a closed recess. Casting 97has a side arm 102 carrying a branch passage 103 communicating withcylindrical passage 101, and the end of side arm 102 carries a nipple104 directed toward nipple 53 on floating valve housing 36. Flexibletube 50 is fitted over nipples 53 and 104 thereby providing a continuousgas passage to valve chamber 37 from the outside of the device throughgas coupling assembly 17 and tube 50. Valve control arm 51 extendsthrough the gas passage of nipple 104 to the intersection with gaspassage 103 and is supported at its fixed end 10S in a hole drilledthrough the wall of arm 102 by a press-tit or by brazing, therebyaffording a rigid support for the xed end of arm 51.

It will thus be seen that there has been provided by this invention amethod and apparatus in which `the various objects hereinabove set forthtogether with many thoroughly practical advantages are successfullyachieved. As various possible embodiments might be made of themechanical features of the above invention and as the art hereindescribed might be varied in various parts, all without departing fromthe scope of the invention, it is to be understood that all matterhereinbefore set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

What I claim is:

l. A resuscitator comprising a casing, a pair of spaced flexiblediaphragms dividing the interior of said casing into three chambers, afloating valve housing suspended by said diaphragms, means for centeringthe valve housing within the casing and preventing it from beingdisplaced angularly, a valve chamber within said housing, the axis ofsaid valve chamber being parallel to the axis of said diaphragms, a gasinlet coupling extending into said casing between said diaphragms, and aflexible gas conduit within said casing connecting said inlet couplingto said valve chamber, said oating housing carrying a pair of gaspassages communicating with the respective ends of said valve chamber, avalve closure element slideable in said valve chamber, and a supportingarm therefor xed at its outer end and extending from the casing wallinto said valve chamber substantially normal to the valve chamberwhereby axial movement of said oating valve housing will shift saidvalve closure element between the ends of said valve chamber,alternatively to close said respective gas passages, said valve housingincluding a venturi passage extending between the middle one of saidthree charnbers and a second of said chambers, and a lirst venturi jetfed by one of said gas passages which is closed by movement of saidvalve housing in a direction away from said second chamber, and a secondventuri jet fed by the other of said gas passages, said first venturijet being directed into said venturi passage to drive gas from saidmiddle chamber and said second jet being directed into said venturipassage to drive gas from said second chamber into said middle chamber,a gas administering conduit extending from said second chamber, saidcasing having an atmospheric opening into the third of said chambers,and a gas escape valve leading out of said middle chamber.

2. The device claimed in claim 1, including means for regulating thetotal gas pressure, both positive and negative, applied to said gasadministering conduit during a cycle of operation.

3. The device claimed in claim l, including means for regulating the gaspressure within said gas administering conduit while gas is beingsupplied into said conduit, and compensating means for regulating thegas pressure within said conduit while gas is being exhausted from saidconduit in relation to the said pressure while gas is being suppliedinto the conduit.

4. The device claimed in claim 1, including means for regulating the gaspressure within said gas administering conduit while gas is beingsupplied into said conduit, in relation to the total positive andnegative gas pressure applied during an inhalation-exhalation cycle.

5. The device claimed in claim 1, including means for regulating the gaspressure applied to promote exhalation to the total positive andnegative gas pressures applied during an exhalation-inhalation cycle.

6. The device claimed in claim l, including means for regulating thetotal positive plus negative pressures applied during an operating cycleand means for regulating the negative pressure applied during part ofthe cycle relative to the total negative plus positive pressuresemployed during a full cycle.

7. The device claimed in claim 1, including means for shiftinginstantaneously from one set of positive-negative pressures to another.

8. The device claimed in claim 1, including means for loading saidhousing member, and means for adjusting said member to control the forceit exerts on said housing.

9. The device claimed in claim 1, including means for acting on saidhousing to bias it and change its resistance to movement and therebyvary the pressures required to move it and consequently the positive andnegative pressures applied to said gas administering conduit, and meansfor substantially instantaneously activating and de-activating saidbiasing means to shift from one of said sets of pressures to another.

10. The device claimed in claim 1, including means for biasing thehousing and means for connecting said biasing means to the housing, anddisconnecting it from the housing, to change the gas pressures employedfrom a positive pressure of substantially 12-16 mm. of mercury and anegative pressure of substantially 9-13 mm. of mercury, to a positivepressure of substantially 25-29 mrn. of mercury and a negative pressureof substantially zero.

11. The device claimed in claim l, in which said casing comprises anannular end member and in which said second chamber comprises one ofsaid diaphragms and a member which tits within said end member and has atubular portion which extends through the opening in the end member,said member being spaced from said end member providing aspace betweenthem, and said end member being provided with a number of ventscommunicating between said space and the surrounding atmosphere, andvalve means in the wall of said member, com- 9 municating between saidsecond chamber and said space.

12. The device claimed in claim 1, in which communication, between said:lrst jet and the said gas passage which is closed by movement of saidvalve housing in a direction away from said second chamber, is providedby an axially bored nut fitting over the proximate-ends of said jetpassage and said gas passage, with its bore aligned With said jetpassage, and a screw for closing said bore.

13. The device claimed in claim 2 in which the means for regulating thetotal gas pressure applied during a cycle comprises a friction member.supported from the casing and bearing on said valve housing, and meansfor increasing and decreasing the force exerted on the housing by saidmember.

14. The device claimed in claim 3 in which the means for regulating thegas pressure exerted in said administering conduit during exhalationcomprises means supported from the casing and extending into contactwith the valve housing and adjustable toward and away from the housing.

15. The device claimed in claim 14 in which said pressure regulatingmeans is mounted in movable support means on the inside of said casingand a slot is provided in the casing wall through which means may beinserted for moving said support means to thereby vary the force exertedby said pressure regulating means on said valve housing.

16. A resuscitator device comprising an inlet conduit adapted to beconnected to a source of gas supply, venturi means including rst andsecond jets for creating positive and negative gas pressuresrespectively, a distributing valve housing having a valve chamber fed bysaid inlet conduit and having first and second jet supply passagesleading to said first and second jets, respectively, and a valve elementmovable between two positions in said valve chamber for alternativelyclosing said jet passages, the gas pressure in said valve chamberresisting the opening of the closed valve passage in both positions ofsaid valve element, a gas chamber supplied with positive and negativegas pressures by said venturi means, `one of the walls of said chamberbeing movable, said valve housing being coupled thereto for controlthereby, and a resilient support arm for said valve element mountedindependently of said valve housing, to shift said valve element fromthe rst to the second of said positions responsive to negative gaspressure in said gas chamber and from the second to the first of saidpositions responsive to positive gas pressure in said gas chamber, meansfor varying the positive pressure and the negative pressure required tomove said valve element, and means for changing the ratio between therequired positive pressure and th required negative pressure.

17. A resuscitator comprising, in combination, a hollow casing having agas administering chamber therein,

10 a exible diaphragm in said casing comprising a wall of said chamber,a valve housing carried by said diaphragm and having a valve chambertherein, a exible gas supply conduit leading into said valve chamber, agas injector jet directed into said gas administering chamber and a gasejector jet directed out of said chamber, said valve housing havingiirst and second gas passages leading from said valve chamber to saidjets, respectively, and a shiftable valve closure element in said valvechamber movable with respect to said valve chamber between a rstposition for closing said first passage and a second position forclosing said second passage, a support for said valve closure elementmounted in said casing independently of said diaphragm, whereby movementof said valve housing by said diaphragm will shift said closure element,means acting when in contact with said housing to bias said housing andthereby increase the pressure required to move said diaphragm in eitherdirection, and toggle switch means for moving said biasing means betweenactive and inactive position.

18. A resuscitator comprising, in combination, a rst gas chamber, asecond gas chamber having a gas administering conduit leading therefrom,a venturi extending from said first to said second gas chamber, a firstjet in said first chamber for projecting a gas into said venturi, asecond jet in said second chamber for projecting a gas into saidventuri, a valve for supplying a gas` alternatively to said first andsecond jets, said first chamber having a gas inlet and outlet passagecommunicating with the atmosphere and an adjustable valve for regulatingthe rate `of gas flow through said passage, thereby to control the rateof gas ow through said venturi, and means for regulating the resistanceof said diaphragm to movement and the positive and negative pressuresrequired to move it.

19. A gas administering device for administering a mixture of gases,comprising, in combination, a first gas chamber, a second gas chamberhaving a gas administering conduit leading therefrom, a diaphragmseparating said chambers, a venturi extending from said first to saidsecond gas chamber, a jet in said first chamber for projecting a firstgas into said venturi, said first chamber having a gas inlet passage foradmitting a second gas thereto, and an adjustable valve for regulatingthe rate `of gas admission through said inlet, thereby to regulate boththe rate of gas ow and the composition of the gas mixture passingthrough the venturi, and means for regulating the resistance of saiddiaphragm to movement to provide a choice between a plurality of sets ofpressures within said gas administering conduit.

References Cited in the iile of this patent UNITED STATES PATENTSGoodner Oct. 4, 1949

